SpiceManagementSystem/app/Models/Spice.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Spice extends Model
{
    protected $fillable = ['name', 'quantity', 'unit', 'piece_weight'];

    public function recipes()
    {
        return $this->belongsToMany(Recipe::class, 'recipes_spices')
                    ->withPivot('amount_in_percent')
                    ->withTimestamps();
    }

    public function stockMovements()
    {
        return $this->hasMany(SpiceStockMovement::class);
    }

    public function recalculateQuantity(): void
    {
        $this->update(['quantity' => $this->stockMovements()->sum('amount')]);
    }

    public function recalculatePieceWeight(): void
    {
        $result = SpiceSupplier::where('spice_id', $this->id)
            ->whereNotNull('weight_g')
            ->where('weight_g', '>', 0)
            ->selectRaw('SUM(weight_g) as total_grams, SUM(amount) as total_pieces')
            ->first();

        if ($result && $result->total_pieces > 0) {
            $this->update(['piece_weight' => round($result->total_grams / $result->total_pieces, 3)]);
        }
    }
}